Category Archives: environment

I think this is the first time I’ve seen anything about a technology that removes toxic materials from both water and soil; it’s usually one or the other. A July 22, 2015 news item on Nanowerk makes the announcement (Note: A link has been removed),

Many human-made pollutants in the environment resist degradation through natural processes, and disrupt hormonal and other systems in mammals and other animals. Removing these toxic materials — which include pesticides and endocrine disruptors such as bisphenol A (BPA) — with existing methods is often expensive and time-consuming.

In a new paper published this week in Nature Communications (“Nanoparticles with photoinduced precipitation for the extraction of pollutants from water and soil”), researchers from MIT [Massachusetts Institute of Technology] and the Federal University of Goiás in Brazil demonstrate a novel method for using nanoparticles and ultraviolet (UV) light to quickly isolate and extract a variety of contaminants from soil and water.

Ferdinand Brandl and Nicolas Bertrand, the two lead authors, are former postdocs in the laboratory of Robert Langer, the David H. Koch Institute Professor at MIT’s Koch Institute for Integrative Cancer Research. (Eliana Martins Lima, of the Federal University of Goiás, is the other co-author.) Both Brandl and Bertrand are trained as pharmacists, and describe their discovery as a happy accident: They initially sought to develop nanoparticles that could be used to deliver drugs to cancer cells.

Brandl had previously synthesized polymers that could be cleaved apart by exposure to UV light. But he and Bertrand came to question their suitability for drug delivery, since UV light can be damaging to tissue and cells, and doesn’t penetrate through the skin. When they learned that UV light was used to disinfect water in certain treatment plants, they began to ask a different question.

“We thought if they are already using UV light, maybe they could use our particles as well,” Brandl says. “Then we came up with the idea to use our particles to remove toxic chemicals, pollutants, or hormones from water, because we saw that the particles aggregate once you irradiate them with UV light.”

A trap for ‘water-fearing’ pollution

The researchers synthesized polymers from polyethylene glycol, a widely used compound found in laxatives, toothpaste, and eye drops and approved by the Food and Drug Administration as a food additive, and polylactic acid, a biodegradable plastic used in compostable cups and glassware.

Nanoparticles made from these polymers have a hydrophobic core and a hydrophilic shell. Due to molecular-scale forces, in a solution hydrophobic pollutant molecules move toward the hydrophobic nanoparticles, and adsorb onto their surface, where they effectively become “trapped.” This same phenomenon is at work when spaghetti sauce stains the surface of plastic containers, turning them red: In that case, both the plastic and the oil-based sauce are hydrophobic and interact together.

If left alone, these nanomaterials would remain suspended and dispersed evenly in water. But when exposed to UV light, the stabilizing outer shell of the particles is shed, and — now “enriched” by the pollutants — they form larger aggregates that can then be removed through filtration, sedimentation, or other methods.

The researchers used the method to extract phthalates, hormone-disrupting chemicals used to soften plastics, from wastewater; BPA, another endocrine-disrupting synthetic compound widely used in plastic bottles and other resinous consumer goods, from thermal printing paper samples; and polycyclic aromatic hydrocarbons, carcinogenic compounds formed from incomplete combustion of fuels, from contaminated soil.

The process is irreversible and the polymers are biodegradable, minimizing the risks of leaving toxic secondary products to persist in, say, a body of water. “Once they switch to this macro situation where they’re big clumps,” Bertrand says, “you won’t be able to bring them back to the nano state again.”

The fundamental breakthrough, according to the researchers, was confirming that small molecules do indeed adsorb passively onto the surface of nanoparticles.

“To the best of our knowledge, it is the first time that the interactions of small molecules with pre-formed nanoparticles can be directly measured,” they write in Nature Communications.

Nano cleansing

Even more exciting, they say, is the wide range of potential uses, from environmental remediation to medical analysis.

The polymers are synthesized at room temperature, and don’t need to be specially prepared to target specific compounds; they are broadly applicable to all kinds of hydrophobic chemicals and molecules.

“The interactions we exploit to remove the pollutants are non-specific,” Brandl says. “We can remove hormones, BPA, and pesticides that are all present in the same sample, and we can do this in one step.”

And the nanoparticles’ high surface-area-to-volume ratio means that only a small amount is needed to remove a relatively large quantity of pollutants. The technique could thus offer potential for the cost-effective cleanup of contaminated water and soil on a wider scale.

“From the applied perspective, we showed in a system that the adsorption of small molecules on the surface of the nanoparticles can be used for extraction of any kind,” Bertrand says. “It opens the door for many other applications down the line.”

This approach could possibly be further developed, he speculates, to replace the widespread use of organic solvents for everything from decaffeinating coffee to making paint thinners. Bertrand cites DDT, banned for use as a pesticide in the U.S. since 1972 but still widely used in other parts of the world, as another example of a persistent pollutant that could potentially be remediated using these nanomaterials. “And for analytical applications where you don’t need as much volume to purify or concentrate, this might be interesting,” Bertrand says, offering the example of a cheap testing kit for urine analysis of medical patients.

The study also suggests the broader potential for adapting nanoscale drug-delivery techniques developed for use in environmental remediation.

“That we can apply some of the highly sophisticated, high-precision tools developed for the pharmaceutical industry, and now look at the use of these technologies in broader terms, is phenomenal,” says Frank Gu, an assistant professor of chemical engineering at the University of Waterloo in Canada, and an expert in nanoengineering for health care and medical applications.

“When you think about field deployment, that’s far down the road, but this paper offers a really exciting opportunity to crack a problem that is persistently present,” says Gu, who was not involved in the research. “If you take the normal conventional civil engineering or chemical engineering approach to treating it, it just won’t touch it. That’s where the most exciting part is.”

The researchers have made this illustration of their work available,

Nanoparticles that lose their stability upon irradiation with light have been designed to extract endocrine disruptors, pesticides, and other contaminants from water and soils. The system exploits the large surface-to-volume ratio of nanoparticles, while the photoinduced precipitation ensures nanomaterials are not released in the environment. Image: Nicolas Bertrand Courtesy: MIT

Sometime in the last few years I was asked about carbon sequestration (or carbon capture) and nanotechnology and had no answer for the question until now (drat!). A July 13, 2015 Rice University (Texas, US) news release (also on EurekAlert) describes some research into buckyballs and the possibility they could be used to confine greenhouse gases,

Rice University scientists are forging toward tunable carbon-capture materials with a new study that shows how chemical changes affect the abilities of enhanced buckyballs to confine greenhouse gases.

The lab of Rice chemist Andrew Barron found last year that carbon-60 molecules (aka buckyballs, discovered at Rice in the 1980s) gain the ability to sequester carbon dioxide when combined with a polymer known as polyethyleneimine (PEI).

Two critical questions – how and how well – are addressed in a new paper in the American Chemical Society journal Energy and Fuels.

The news release expands on the theme,

The amine-rich combination of C60 and PEI showed its potential in the previous study to capture emissions of carbon dioxide, a greenhouse gas, from such sources as industrial flue gases and natural-gas wells.

In the new study, the researchers found pyrolyzing the material – heating it in an oxygen-free environment – changes its chemical composition in ways that may someday be used to tune what the scientists call PEI-C60 for specific carbon-capture applications.

“One of the things we wanted to see is at what point, chemically, it converts from being something that absorbed best at high temperature to something that absorbed best at low temperature,” Barron said. “In other words, at what point does the chemistry change from one to the other?”

Lead author Enrico Andreoli pyrolyzed PEI-C60 in argon at various temperatures from 100 to 1,000 degrees Celsius (212 to 1,832 degrees Fahrenheit) and then evaluated each batch for carbon uptake.

He discovered the existence of a transition point at 200 C, a boundary between the material’s ability to soak in carbon dioxide through chemical means as opposed to physical absorption.

The material that was pyrolyzed at low temperatures became gooey and failed at pulling in carbon from high-temperature sources by chemical means. The opposite was true for PEI-C60 pyrolyzed at high heat. The now-porous, brittle material became better in low-temperature environments, physically soaking up carbon dioxide molecules.

At 200 C, they found the heat treatment breaks the polymer’s carbon-nitrogen bonds, leading to a drastic decrease in carbon capture by any means.

“One of the goals was to see if can we make this a little less gooey and still have chemical uptake, and the answer is, not really,” Barron said. “It flips from one process to the other. But this does give us a nice continuum of how to get from one to the other.”

Andreoli found that at its peak, untreated PEI-C60 absorbed more than a 10th of its weight in carbon dioxide at high temperatures (0.13 grams per gram of material at 90 C). Pyrolyzed PEI-C60 did nearly as well at low temperatures (0.12 grams at 25 C).

The researchers, with an eye on potential environmental benefits, continue to refine their process. “This has definitely pointed us in the right direction,” Barron said.

As engineered nanomaterials increasingly find their way into commercial products, researchers who study the potential environmental or health impacts of those materials face a growing challenge to accurately measure and characterize them. These challenges affect measurements of basic chemical and physical properties as well as toxicology assessments.

To help nano-EHS (Environment, Health and Safety)researchers navigate the often complex measurement issues, the National Institute of Standards and Technology (NIST) has launched a new website devoted to NIST-developed (or co-developed) and validated laboratory protocols for nano-EHS studies.

A July 1, 2015 NIST news release on EurekAlert, which originated the news item, offers more details about the information available through the web portal,

In common lab parlance, a “protocol” is a specific step-by-step procedure used to carry out a measurement or related activity, including all the chemicals and equipment required. Any peer-reviewed journal article reporting an experimental result has a “methods” section where the authors document their measurement protocol, but those descriptions are necessarily brief and condensed, and may lack validation of any sort. By comparison, on NIST’s new Protocols for Nano-EHS website the protocols are extraordinarily detailed. For ease of citation, they’re published individually–each with its own unique digital object identifier (DOI).

The protocols detail not only what you should do, but why and what could go wrong. The specificity is important, according to program director Debra Kaiser, because of the inherent difficulty of making reliable measurements of such small materials. “Often, if you do something seemingly trivial–use a different size pipette, for example–you get a different result. Our goal is to help people get data they can reproduce, data they can trust.”

A typical caution, for example, notes that if you’re using an instrument that measures the size of nanoparticles in a solution by how they scatter light, it’s important also to measure the transmission spectrum of the particles if they’re colored, because if they happen to absorb light strongly at the same frequency as your instrument, the result may be biased.

“These measurements are difficult because of the small size involved,” explains Kaiser. “Very few new instruments have been developed for this. People are adapting existing instruments and methods for the job, but often those instruments are being operated close to their limits and the methods were developed for chemicals or bulk materials and not for nanomaterials.”

“For example, NIST offers a reference material for measuring the size of gold nanoparticles in solution, and we report six different sizes depending on the instrument you use. We do it that way because different instruments sense different aspects of a nanoparticle’s dimensions. An electron microscope is telling you something different than a dynamic light scattering instrument, and the researcher needs to understand that.”

The nano-EHS protocols offered by the NIST site, Kaiser says, could form the basis for consensus-based, formal test methods such as those published by ASTM and ISO.

NIST’s nano-EHS protocol site currently lists 12 different protocols in three categories: sample preparation, physico-chemical measurements and toxicological measurements. More protocols will be added as they are validated and documented. Suggestions for additional protocols are welcome at nanoprotocols@nist.gov.

The next item concerns European nanomedicine.

CEA-LETI and Europe’s first nanomedicine characterization laboratory

A July 1, 2015 news item on Nanotechnology Now describes the partnership which has led to launch of the new laboratory,

CEA-Leti today announced the launch of the European Nano-Characterisation Laboratory (EU-NCL) funded by the European Union’s Horizon 2020 research and innovation programm[1]e. Its main objective is to reach a level of international excellence in nanomedicine characterisation for medical indications like cancer, diabetes, inflammatory diseases or infections, and make it accessible to all organisations developing candidate nanomedicines prior to their submission to regulatory agencies to get the approval for clinical trials and, later, marketing authorization.

“As reported in the ETPN White Paper[2], there is a lack of infrastructure to support nanotechnology-based innovation in healthcare,” said Patrick Boisseau, head of business development in nanomedicine at CEA-Leti and chairman of the European Technology Platform Nanomedicine (ETPN). “Nanocharacterisation is the first bottleneck encountered by companies developing nanotherapeutics. The EU-NCL project is of most importance for the nanomedicine community, as it will contribute to the competiveness of nanomedicine products and tools and facilitate regulation in Europe.”

EU-NCL is partnered with the sole international reference facility, the Nanotechnology Characterization Lab of the National Cancer Institute in the U.S. (US-NCL)[3], to get faster international harmonization of analytical protocols.

“We are excited to be part of this cooperative arrangement between Europe and the U.S.,” said Scott E. McNeil, director of U.S. NCL. “We hope this collaboration will help standardize regulatory requirements for clinical evaluation and marketing of nanomedicines internationally. This venture holds great promise for using nanotechnologies to overcome cancer and other major diseases around the world.”

The «European Nanomedicine Characterization Laboratory» (EU-NCL), which was launched on 1 June 2015, has a clear-cut goal: to help bring more nanomedicine candidates into the clinic and on the market, for the benefit of patients and the European pharmaceutical industry. To achieve this, EU-NCL is partnered with the sole international reference facility, the «Nanotechnology Characterization Laboratory» (US-NCL) of the US-National Cancer Institute, to get faster international harmonization of analytical protocols. EU-NCL is also closely connected to national medicine agencies and the European Medicines Agency to continuously adapt its analytical services to requests of regulators. EU-NCL is designed, organized and operated according to the highest EU regulatory and quality standards. «We are excited to be part of this cooperative project between Europe and the U.S.,» says Scott E. McNeil, director of US-NCL. «We hope this collaboration will help standardize regulatory requirements for clinical evaluation and marketing of nanomedicines internationally. This venture holds great promise for using nanotechnologies to overcome cancer and other major diseases around the world.»

Nine partners from eight countries

EU-NCL, which is funded by the EU for a four-year period with nearly 5 million Euros, brings together nine partners from eight countries: CEA-Tech in Leti and Liten, France, the coordinator of the project; the Joint Research Centre of the European Commission in Ispra, Italy; European Research Services GmbH in Münster Germany; Leidos Biomedical Research, Inc. in Frederick, USA; Trinity College in Dublin, Ireland; SINTEF in Oslo, Norway; the University of Liverpool in the UK; Empa, the Swiss Federal Laboratories for Materials Science and Technology in St. Gallen, Switzerland; Westfälische Wilhelms-Universität (WWU) and Gesellschaft für Bioanalytik, both in Münster, Germany. Together, the partnering institutions will provide a trans-disciplinary testing infrastructure covering a comprehensive set of preclinical characterization assays (physical, chemical, in vitro and in vivo biological testing), which will allow researchers to fully comprehend the biodistribution, metabolism, pharmacokinetics, safety profiles and immunological effects of their medicinal nano-products. The project will also foster the use and deployment of standard operating procedures (SOPs), benchmark materials and quality management for the preclinical characterization of medicinal nano-products. Yet another objective is to promote intersectoral and interdisciplinary communication among key drivers of innovation, especially between developers and regulatory agencies.

The goal: to bring safe and efficient nano-therapeutics faster to the patient

Within EU-NCL, six analytical facilities will offer transnational access to their existing analytical services for public and private developers, and will also develop new or improved analytical assays to keep EU-NCL at the cutting edge of nanomedicine characterization. A complementary set of networking activities will enable EU-NCL to deliver to European academic or industrial scientists the high-quality analytical services they require for accelerating the industrial development of their candidate nanomedicines. The Empa team of Peter Wick at the «Particles-Biology Interactions» lab will be in charge of the quality management of all analytical methods, a key task to guarantee the best possible reproducibility and comparability of the data between the various analytical labs within the consortium. «EU-NCL supports our research activities in developing innovative and safe nanomaterials for healthcare within an international network, which will actively shape future standards in nanomedicine and strengthen Empa as an enabler to facilitate the transfer of novel nanomedicines from bench to bedside», says Wick.

There’s a team of researchers at the University of Wisconsin-Madison working to substitute silicon used in computer chips with cellulose derived from wood (my May 27, 2015 posting). Their latest effort, featuring mobile electronics, is described in a July 1, 2015 news item on Azonano,

A report published by the U.S. Environmental Protection Agency in 2012 showed that about 152 million mobile devices are discarded every year, of which only 10 percent is recycled — a legacy of waste that consumes a tremendous amount of natural resources and produces a lot of trash made from expensive and non-biodegradable materials like highly purified silicon.

Now researchers from the University of Wisconsin-Madison have come up with a new solution to alleviate the environmental burden of discarded electronics. They have demonstrated the feasibility of making microwave biodegradable thin-film transistors from a transparent, flexible biodegradable substrate made from inexpensive wood, called cellulose nanofibrillated fiber (CNF). This work opens the door for green, low-cost, portable electronic devices in future.

“We found that cellulose nanofibrillated fiber based transistors exhibit superior performance as that of conventional silicon-based transistors,” said Zhenqiang Ma, the team leader and a professor of electrical and computer engineering at the UW-Madison. “And the bio-based transistors are so safe that you can put them in the forest, and fungus will quickly degrade them. They become as safe as fertilizer.”

Nowadays, the majority of portable electronics are built on non-renewable, non-biodegradable materials such as silicon wafers, which are highly purified, expensive and rigid substrates, but cellulose nanofibrillated fiber films have the potential to replace silicon wafers as electronic substrates in environmental friendly, low-cost, portable gadgets or devices of the future.

Cellulose nanofibrillated fiber is a sustainable, strong, transparent nanomaterial made from wood. Compared to other polymers like plastics, the wood nanomaterial is biocompatible and has relatively low thermal expansion coefficient, which means the material won’t change shape as the temperature changes. All these superior properties make cellulose nanofibril an outstanding candidate for making portable green electronics.

To create high-performance devices, Ma’s team employed silicon nanomembranes as the active material in the transistor — pieces of ultra-thin films (thinner than a human hair) peeled from the bulk crystal and then transferred and glued onto the cellulose nanofibrill substrate to create a flexible, biodegradable and transparent silicon transistor.To create high-performance devices, Ma’s team employed silicon nanomembranes as the active material in the transistor — pieces of ultra-thin films (thinner than a human hair) peeled from the bulk crystal and then transferred and glued onto the cellulose nanofibrill substrate to create a flexible, biodegradable and transparent silicon transistor.

But to make portable electronics, the biodegradable transistor needed to be able to operate at microwave frequencies, which is the working range of most wireless devices. The researchers thus conducted a series of experiments such as measuring the current-voltage characteristics to study the device’s functional performance, which finally showed the biodegradable transistor has superior microwave-frequency operation capabilities comparable to existing semiconductor transistors.

“Biodegradable electronics provide a new solution for environmental problems brought by consumers’ pursuit of quickly upgraded portable devices,” said Ma. “It can be anticipated that future electronic chips and portable devices will be much greener and cheaper than that of today.”

Next, Ma and colleagues plan to develop more complicated circuit system based on the biodegradable transistors.

The latest announcement (this one about nanosensors) from the US National Nanotechnology Coordination Office (NNCO) on behalf of the US National Nanotechnology (NNI) gets a little confusing but hopefully I’ve managed to clarify things.

The National Nanotechnology Coordination Office (NNCO) is pleased to announce the launch of a workshop report and a web portal, efforts coordinated through and in support of the Nanotechnology Signature Initiative ‘Nanotechnology for Sensors and Sensors for Nanotechnology: Improving and Protecting Health, Safety, and the Environment’ (Sensors NSI). Together, these resources help pave the path forward for the development and commercialization of nanotechnology-enabled sensors and sensors for nanotechnology.

A June 19, 2015 NNCO news release on EurekAlert, which originated the news item, provides details about the report, the new portal, and the new series of webinars,

The workshop report is a summary of the National Nanotechnology Initiative (NNI)-sponsored event held September 11-12, 2014, entitled ‘Sensor Fabrication, Integration, and Commercialization Workshop.’ The goal of the workshop was to identify and discuss challenges that are faced by the sensor development community during the fabrication, integration, and commercialization of sensors, particularly those employing or addressing issues of nanoscale materials and technologies.

Workshop attendees, including sensor developers and representative from Federal agencies, identified ways to help facilitate the commercialization of nanosensors, which include:

Enhancing communication among researchers, developers, manufacturers, customers, and the Federal Government agencies that support and regulate sensor development.

Leveraging resources by building testbeds for sensor developers.

Improving access of university and private researchers to federally supported facilities.

Encouraging sensor developers to consider and prepare for market and regulatory requirements early in the development process.

In response to discussions at the workshop, the NNI has also launched an NSI Sensors web portal to share information on the sensors development landscape, including funding agencies and opportunities, federally supported facilities, regulatory guidance, and published standards. Ongoing dialogue and collaboration among various stakeholder groups will be critical to effectively transitioning nanosensors to market and to meeting the U.S. need for a reliable and robust sensor infrastructure.

On Thursday June 25, 2015, from noon to 1 pm EDT, NNCO will host a webinar to summarize the highlights from the 2014 ‘Sensor Fabrication, Integration, and Commercialization Workshop’ and to introduce the newly developed Sensors NSI Web Portal. The webinar will also feature a Q&A segment with members of the public. Questions for the panel can be submitted to webinar@nnco.nano.gov from June 18 through the end of the webinar at 1 pm EDT on June 25, 2015.

Here’s the portal for what they’ve called the NSI [Nanotechnology Signature Initiative]: Nanotechnology for Sensors and Sensors for Nanotechnology — Improving and Protecting, Health Safety, and the Environment, also known as, Sensors NSI Web Portal.

The National Nanotechnology Coordination Office (NNCO) will host a webinar to summarize the highlights from the September 2014 Sensor Fabrication, Integration, and Commercialization Workshop and to introduce the newly developed Sensors NSI Web Portal, which was created to share information on the sensors development landscape, including Federal program and funding opportunities, federally supported facilities, regulatory guidance, and published standards.

On Thursday, June 25, 2015, from 12 noon to 1 pm EDT, Federal panelists will begin the event with a discussion of the findings from the Sensor Fabrication, Integration, and Commercialization Workshop, as well as a demonstration of the resources available on the Sensors NSI Portal. [emphasis mine]

Federal panelists at the event will include:

Dr. Hongda Chen, National Program Leader, National Institute of Food and Agriculture.

Dr. Heather Evans, Senior Program Analyst, National Institute of Standards and Technology.

This event will feature a Q&A segment with members of the public. Questions for the panel can be submitted to webinar@nnco.nano.gov from June 18 through the end of the webinar at 1 pm on June 25, 2015. The moderator reserves the right to group similar questions and to omit questions that are either repetitive or not directly related to the topic. Due to time constraints, it may not be possible to answer all questions.

You can find the link to register at the end/bottom of the event page.

The NNCO does have one other Public Webinar series, ‘NNCO Small- and Medium-sized Business Enterprise (SME) Webinar Series’. They have archived previously held webinars in this series. There are no upcoming webinars in this series currently scheduled.

Researchers at Columbia University (US) are on quite a publishing binge lately. The latest is a biomimicry story where researchers (from Columbia amongst other universities and including Brookhaven National Laboratory, which has issued its own news release) have taken a very close look at Saharan silver ants to determine how they stay cool in one of the hottest climates in the world. From a June 18, 2015 Columbia University news release (also on EurekAlert), Note: Links have been removed,

Nanfang Yu, assistant professor of applied physics at Columbia Engineering, and colleagues from the University of Zürich and the University of Washington, have discovered two key strategies that enable Saharan silver ants to stay cool in one of the hottest terrestrial environments on Earth. Yu’s team is the first to demonstrate that the ants use a coat of uniquely shaped hairs to control electromagnetic waves over an extremely broad range from the solar spectrum (visible and near-infrared) to the thermal radiation spectrum (mid-infrared), and that different physical mechanisms are used in different spectral bands to realize the same biological function of reducing body temperature. Their research, “Saharan silver ants keep cool by combining enhanced optical reflection and radiative heat dissipation,” is published June 18 [2015] in Science magazine.

The Columbia University news release expands on the theme,

“This is a telling example of how evolution has triggered the adaptation of physical attributes to accomplish a physiological task and ensure survival, in this case to prevent Saharan silver ants from getting overheated,” Yu says. “While there have been many studies of the physical optics of living systems in the ultraviolet and visible range of the spectrum, our understanding of the role of infrared light in their lives is much less advanced. Our study shows that light invisible to the human eye does not necessarily mean that it does not play a crucial role for living organisms.”

The project was initially triggered by wondering whether the ants’ conspicuous silvery coats were important in keeping them cool in blistering heat. Yu’s team found that the answer to this question was much broader once they realized the important role of infrared light. Their discovery that there is a biological solution to a thermoregulatory problem could lead to the development of novel flat optical components that exhibit optimal cooling properties.

“Such biologically inspired cooling surfaces will have high reflectivity in the solar spectrum and high radiative efficiency in the thermal radiation spectrum,” Yu explains. “So this may generate useful applications such as a cooling surface for vehicles, buildings, instruments, and even clothing.”

Saharan silver ants (Cataglyphis bombycina) forage in the Saharan Desert in the full midday sun when surface temperatures reach up to 70°C (158°F), and they must keep their body temperature below their critical thermal maximum of 53.6°C (128.48°F) most of the time. In their wide-ranging foraging journeys, the ants search for corpses of insects and other arthropods that have succumbed to the thermally harsh desert conditions, which they are able to endure more successfully. Being most active during the hottest moment of the day also allows these ants to avoid predatory desert lizards. Researchers have long wondered how these tiny insects (about 10 mm, or 3/8” long) can survive under such thermally extreme and stressful conditions.

Using electron microscopy and ion beam milling, Yu’s group discovered that the ants are covered on the top and sides of their bodies with a coating of uniquely shaped hairs with triangular cross-sections that keep them cool in two ways. These hairs are highly reflective under the visible and near-infrared light, i.e., in the region of maximal solar radiation (the ants run at a speed of up to 0.7 meters per second and look like droplets of mercury on the desert surface). The hairs are also highly emissive in the mid-infrared portion of the electromagnetic spectrum, where they serve as an antireflection layer that enhances the ants’ ability to offload excess heat via thermal radiation, which is emitted from the hot body of the ants to the cold sky. This passive cooling effect works under the full sun whenever the insects are exposed to the clear sky.

“To appreciate the effect of thermal radiation, think of the chilly feeling when you get out of bed in the morning,” says Yu. “Half of the energy loss at that moment is due to thermal radiation since your skin temperature is temporarily much higher than that of the surrounding environment.”

The researchers found that the enhanced reflectivity in the solar spectrum and enhanced thermal radiative efficiency have comparable contributions to reducing the body temperature of silver ants by 5 to 10 degrees compared to if the ants were without the hair cover. “The fact that these silver ants can manipulate electromagnetic waves over such a broad range of spectrum shows us just how complex the function of these seemingly simple biological organs of an insect can be,” observes Norman Nan Shi, lead author of the study and PhD student who works with Yu at Columbia Engineering.

Yu and Shi collaborated on the project with Rüdiger Wehner, professor at the Brain Research Institute, University of Zürich, Switzerland, and Gary Bernard, electrical engineering professor at the University of Washington, Seattle, who are renowned experts in the study of insect physiology and ecology. The Columbia Engineering team designed and conducted all experimental work, including optical and infrared microscopy and spectroscopy experiments, thermodynamic experiments, and computer simulation and modeling. They are currently working on adapting the engineering lessons learned from the study of Saharan silver ants to create flat optical components, or “metasurfaces,” that consist of a planar array of nanophotonic elements and provide designer optical and thermal radiative properties.

Yu and his team plan next to extend their research to other animals and organisms living in extreme environments, trying to learn the strategies these creatures have developed to cope with harsh environmental conditions.

“Animals have evolved diverse strategies to perceive and utilize electromagnetic waves: deep sea fish have eyes that enable them to maneuver and prey in dark waters, butterflies create colors from nanostructures in their wings, honey bees can see and respond to ultraviolet signals, and fireflies use flash communication systems,” Yu adds. “Organs evolved for perceiving or controlling electromagnetic waves often surpass analogous man-made devices in both sophistication and efficiency. Understanding and harnessing natural design concepts deepens our knowledge of complex biological systems and inspires ideas for creating novel technologies.”

Next, there’s the perspective provided by Brookhaven National Laboratory in a June 18, 2015 news item on Nanowerk (Note: It is very similar to the Columbia University news release but it takes a turn towards the technical challenges as you’ll see if you keep reading),

The paper, published by Columbia Engineering researchers and collaborators—including researchers from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory—describes how the nanoscale structure of the hairs helps increase the reflectivity of the ant’s body in both visible and near-infrared wavelengths, allowing the insects to deflect solar radiation their bodies would otherwise absorb. The hairs also enhance emissivity in the mid-infrared spectrum, allowing heat to dissipate efficiently from the hot body of the ants to the cool, clear sky.

A June 18, 2015 BNL news release by Alasdair Wilkins, which originated the Nanowerk news item, describes the collaboration between the researchers and the special adjustments made to the equipment in service of this project (Note: A link has been removed),

In a typical experiment involving biological material such as nanoscale hairs, it would usually be sufficient to use an electron microscope to create an image of the surface of the specimen. This research, however, required Yu’s group to look inside the ant hairs and produce a cross-section of the structure’s interior. The relatively weak beam of electrons from a standard electron microscope would not be able to penetrate the surface of the sample.

The CFN’s dual beam system solves the problem by combining the imaging of an electron microscope with a much more powerful beam of gallium ions. With 31 protons and 38 neutrons, each gallium ion is about 125,000 times more massive than an electron, and massive enough to create dents in the nanoscale structure – like throwing a stone against a wall. The researchers used these powerful beams to drill precise cuts into the hairs, revealing the crucial information hidden beneath the surface. Indeed, this particular application, in which the system was used to investigate a biological problem, was new for the team at CFN.

“Conventionally, this tool is used to produce cross-sections of microelectronic circuits,” said Camino. “The focused ion beam is like an etching tool. You can think of it like a milling tool in a machine shop, but at the nanoscale. It can remove material at specific places because you can see these locations with the SEM. So locally you remove material and you look at the under layers, because the cuts give you access to the cross section of whatever you want to look at.”

The ant hair research challenged the CFN team to come up with novel solutions to investigate the internal structures without damaging the more delicate biological samples.

“These hairs are very soft compared to, say, semiconductors or crystalline materials. And there’s a lot of local heat that can damage biological samples. So the parameters have to be carefully tuned not to do much damage to it,” he said. “We had to adapt our technique to find the right conditions.”

Another challenge lay in dealing with the so-called charging effect. When the dual beam system is trained on a non-conducting material, electrons can build up at the point where the beams hit the specimen, distorting the resulting image. The team at CFN was able to solve this problem by placing thin layers of gold over the biological material, making the sample just conductive enough to avoid the charging effect.

Revealing Reflectivity

While Camino’s team focused on helping Yu’s group investigate the structure of the ant hairs, Matthew Sfeir’s work with high-brightness Fourier transform optical spectroscopy helped to reveal how the reflectivity of the hairs helped Saharan silver ants regulate temperature. Sfeir’s spectrometer revealed precisely how much those biological structures reflect light across multiple wavelengths, including both visible and near-infrared light.

“It’s a multiplexed measurement,” Sfeir said, explaining his team’s spectrometer. “Instead of tuning through this wavelength and this wavelength, that wavelength, you do them all in one swoop to get all the spectral information in one shot. It gives you very fast measurements and very good resolution spectrally. Then we optimize it for very small samples. It’s a rather unique capability of CFN.”

Sfeir’s spectroscopy work draws on knowledge gained from his work at another key Brookhaven facility: the original National Synchrotron Light Source, where he did much of his postdoc work. His experience was particularly useful in analyzing the reflectivity of the biological structures across many different wavelengths of the electromagnetic spectrum.

“This technique was developed from my experience working with the infrared synchrotron beamlines,” said Sfeir. “Synchrotron beamlines are optimized for exactly this kind of thing. I thought, ‘Hey, wouldn’t it be great if we could develop a similar measurement for the type of solar devices we make at CFN?’ So we built a bench-top version to use here.”

Fascinating, non? At last, here’s a link to and a citation for the paper,

I keep hearing about the possibilities for better (less polluting, more energy efficient, etc.) building construction materials but there never seems to be much progress. A June 15, 2015 news item on Nanowerk, which suggests some serious efforts are being made in Scandinavia, may help to explain the delay,

It isn’t cars and vehicle traffic that produce the greatest volumes of climate gas emissions – it’s our own homes. But new research will soon be putting an end to all that!

The building sector is currently responsible for 40% of global energy use and climate gas emissions. This is an under-communicated fact in a world where vehicle traffic and exhaust emissions get far more attention.

In the future, however, we will start to see construction materials and high-tech systems integrated into building shells that are specifically designed to remedy this situation. Such systems will be intelligent and multifunctional. They will consume less energy and generate lower levels of harmful climate gas emissions.

With this objective in mind, researchers at SINTEF are currently testing microscopic nanoparticles as insulation materials, applying voltages to window glass and facades as a means of saving energy, and developing solar cells that prevent the accumulation of snow and ice.

…

Research Director Susie Jahren and Research Manager Petra Rüther are heading SINTEF’s strategic efforts in the field of future construction materials. They say that although there are major commercial opportunities available in the development of green and low carbon building technologies, the construction industry is somewhat bound by tradition and unable to pay for research into future technology development. [emphasis mine]

SINTEF researcher Bente Gilbu Tilset is sitting in her office in Forskningsveien 1 in Oslo [Norway]. She and her colleagues are looking into the manufacture of super-insulation materials made up of microscopic nanospheres.

“Our aim is to create a low thermal conductivity construction material “, says Tilset. “When gas molecules collide, energy is transferred between them. If the pores in a given material are small enough, for example less than 100 nanometres in diameter, a molecule will collide more often with the pore walls than with other gas molecules. This will effectively reduce the thermal conductivity of the gas. So, the smaller the pores, the lower the conductivity of the gas”, she says.

…

[Solar cells]

As part of the project “Bygningsintegrerte solceller for Norge” (Building Integrated Photovoltaics, BIPV Norway), researchers from SINTEF, NTNU, the IFE [IFE Group, privately owned company, located in Sweden] and Teknova [company created by the Nordic Institute for Studies in Innovation {NIFU}, located in Norway], are planning to look into how we can utilise solar cells as integral housing construction components, and how they can be adapted to Norwegian daylight and climatic conditions.

One of the challenges is to develop a solar cell which prevents the accumulation of snow and ice. The cells must be robust enough to withstand harsh wind and weather conditions and have lifetimes that enable them to function as electricity generators.

…

[Energy]

Today, we spend 90 per cent of our time indoors. This is as much as three times more than in the 1950s. We are also letting less daylight into our buildings as a result of energy considerations and construction engineering requirements. Research shows that daylight is very important to our health, well-being and biological rhythms. It also promotes productivity and learning. So the question is – is it possible to save energy and get the benefits of greater exposure to daylight?

Technologies involving thermochromic, photochromic and electrochromic pigments can help us to control how sunlight enters our buildings, all according to our requirements for daylight and warmth from the sun.

…

Self-healing concrete

Every year, between 40 and 120 million Euros are spent in Europe on the maintenance of bridges, tunnels and construction walls. These time-consuming and costly activities have to be reduced, and the project CAPDESIGN is aiming to make a contribution in this field.

The objective of the project is to produce concrete that can be ‘restored’ after being exposed to loads and stresses by means of self-healing agents that prevent the formation of cracks. The method involves mixing small capsules into the wet concrete before it hardens. These remain in the matrix until loads or other factors threaten to crack it. The capsules then burst and the self-healing agents are released to repair the structure.

At SINTEF, researchers are working with the material that makes up the capsule shells. The shell has to be able to protect the self-healing agent in the capsules for an extended period and then, under the right conditions, break down and release the agents in response to the formation of cracks caused by temperature, pH, or a load or stress resulting from an impact or shaking. At the same time, the capsules must not impair the ductility or the mechanical properties of the newly-mixed concrete.

…

You’ll notice most of the research seems to be taking place in Norway. I suspect that is due to the story having come from a joint Norwegian Norwegian University of Science and Technology (NTNU)/SINTEF, website, Gemini.no/en. Anyone wishing to test their Norwegian readings skills need only omit ‘/en’ from the URL.

A June 8, 2015 news item on Nanowerk features a European Union (EU) Framework Programme 7 (FP7) nanotechnology risk management project and survey,

The EU FP7 Sustainable Nanotechnologies (SUN) project is based on the idea that the current knowledge on environmental and health risks of nanomaterials – while limited – can nevertheless guide nanomanufacturing to avoid liabilities if an integrated approach addressing the complete product lifecycle is applied. SUN aims to evaluate the risks along the supply chains of engineered nanomaterials and incorporate the results into tools and guidelines for sustainable nanomanufacturing.

… A key objective of Sustainable Nanotechnologies (SUN) is to build the SUN Decision Support System (SUNDS) to facilitate safe and sustainable nanomanufacturing and risk management. It will integrate tools for ecological and human health risk assessment, lifecycle assessment, economic assessment and social impact assessment within a sustainability assessment framework. We are currently developing the Technological Alternatives and Risk Management Measures (TARMM) inventory and are looking for companies to fill in a short survey.

… We would appreciate responses from personnel of companies involved in nanotechnology-related activities who are familiar with the risk management practices.

You can go here to take the survey. The focus is on companies and there don’t seem to be any geographic requirements such as only EU companies can participate.

The US National Nanotechnology Coordination Office (NNCO) on behalf of the National Nanotechnology Initiative (NNI) has announced the winners for its first, ‘Tiny Science. Big Impacts. Cool Videos.’ contest in a June 5, 2015 news item on Nanowerk,

The National Nanotechnology Coordination Office (NNCO) is pleased to announce the winners of the first Tiny Science. Big Impacts. Cool Videos. nanotechnology video contest for students. Abelardo Colon and Jennifer Gill from the University of Puerto Rico, Rio Piedras, Nanoscience and Nanotechnology Research Lab won the top honors for their video entitled Chlorination-less. The video explains a new method for disinfecting drinking water using a nanodiamond powder. This nanotechnology-enabled method can kill bacteria, is biocompatible, and is reusable, making it a good alternative to traditional chlorination. Congratulations Abelardo and Jennifer!

Videos submitted by students from universities across the United States and U.S. territories, were posted on NanoTube, the official National Nanotechnology Initiative (NNI) YouTube channel, for public voting. The winning video was chosen by representatives from the NNI member agencies from the top two videos identified by public voting. This video will be featured on Nano.gov for the next month. For more information on the Tiny Science. Big Impacts. Cool Videos. contest rules and judges, visit the student video contest page on Nano.gov.

“Access to clean water is a major international issue that must not be ignored. Our research is finding a new method for the disinfection of drinking water. Even so, chlorination is the most common treatment for the disinfection of drinking water, but has a lot of disadvantages. Disinfectant by-products (DBP’s) produced by the chlorine disinfection process can cause health problems such as cancer to humans that drink water or inhale vapor. Also some bacteria are able to adapt to this chemical treatment. This is why we are proposing a physical treatment using Ultra Dispersed Diamond (UDD) for the disinfection of drinking water. The UDD is a nanodiamond powder, which has bactericidal properties and is biocompatible. After applying the UDD material to the contaminated water we have promising results. There was a reduction of fecal E. coli colonies as time passed and the density of the material increases. This process will be healthier, cheaper, and more environmentally friendly since it is reusable.”

Graduate students, will your research lead to nanotechnologies that impact our daily lives? Submit videos that demonstrate how your nanotechnology research will bring solutions to real-world problems. …

Email submissions information to NNCOvideos@gmail.com and include:

Name and affiliation:

Submissions will be accepted from teams and from individuals. A lead contact person must be designated for team submissions. The order in which names are listed in the submission is the order in which they will appear on the NNI public voting page, the NNI YouTube channel, and on Nano.gov.

Description (150 words or less): Explain your research, use plain language and avoid jargon. Concentrate on what problem your research will help to solve.

Title of uploaded video: It should be the same as the video file name you upload using Google Drive.

Releases for people appearing in the video: A release form is available here; print, collect signatures, scan, and email us electronic copies.

Laboratory website: Include link to the lab where you work, if available

Funding source: Include funding agency, program manager, and award/grant number, if possible

Upload videos using Google Drive to NNCOvideos@gmail.com:

Video Criteria

Video length should be between 2.5 and 3 minutes.

Maximum file size is 2 GB

File type must be H.264, MP4, FLV, or MOV

Use a camera that can shoot videos at least 1280 x 720 pixels in size.

Save video file as the title listed on emailed submission information

Remember to avoid jargon while explaining your research

Collect signed releases (available here) from any recognizable individual appearing in your video

You are allowed to have others (e.g., film students) produce the video. If you put your own video together make sure everything is well lit. Fluorescent overhead lights aren’t the best, try to use natural or focused light if you can. Pay attention to sound quality; use a good microphone and listen for background noise. Watch for too much clutter in the background of your scenes, this can be distracting.

A June 4, 2015 news item on phys.org features research that could be very helpful in understanding the impact that engineered nanoparticles (ENP) have on the water in our environment,

Researchers of Wageningen University (Netherlands) provide the world’s first spatiotemporally explicit model that simulates the behaviour and fate of engineered nanoparticles (ENPs) in surface waters. Wageningen researcher Bart Koelmans: “This is important in order to assure safe nanotechnology. We do need to have an assessment of the risks of ENPs to man and the environment.”

Nanotechnology is developing fast, with the fast growing emission of less than 100 nm engineered nanoparticles as a consequence. ENPs are hard to measure in the environment so that exposure assessments have to rely on modelling. Previous models could only predict average background concentrations on a continental or national scale.

The new NanoDUFLOW model however, developed by Joris Quik, Jeroen de Klein and Bart Koelmans and recently described in Water Research magazine, is capable of simulating the concentrations of ENPs, and their homo- and heteroaggregates in space and time, for any hydrological flow regime of a river. Under the hood of NanoDUFLOW is an ‘engine’ that calculates all relevant interactions among 35 types of particles including the ENPs, and that decides upon aggregation, settling or prolonged flow in the river. The rate of these interactions depends on the flow conditions in the river, which are calculated in the hydrology module of NanoDUFLOW. This module can be set to match the channel structure of any catchment as defined by the user, allowing for a great flexibility.

Development of the model

Development of the model took a long and winding road. ENPs are emerging chemicals with unique properties, which implies that some new process descriptions needed to be developed. One of the main parameters in this new type of models is the attachment efficiency. The attachment efficiency is the chance that two particles stay together when they collide, a chance that depends on the nature of the colliding particles and the chemistry of the water. A smart calculation method needed to be developed that enabled the estimation of the attachment efficiency from laboratory experiments with ENPs and natural particles and waters collected in the field.

Using NanoDUFLOW for the risk assessment of nanomaterials

In order to assure safe nanotechnology, society calls for an assessment of the risks of ENPs to man and the environment. A risk assessment for ENPs requires an assessment of ENP exposure, and of the effects caused by ENPs, which then can be compared in a risk characterisation. Whereas previous screening-level models still may be first choice for lower tiers in the risk assessment, NanoDUFLOW is believed to be useful for higher tiers of the risk assessment, where site specific risks need to be addressed. Simulations with NanoDUFLOW showed the occurrence of clear ENP contamination ‘hot spots’ in the water column and in sediments. Furthermore, NanoDUFLOW was capable of simulating the speciation of ENPs over different size fractions. This speciation defines the ecotoxicologically relevant fractions of ENPs, for a variety of species traits. Also in this respect NanoDUFLOW will add to refining the risk assessment for ENPs.